Dial indicators are typically used with milling and turning machines in order to measure various parameters of the piece being milled and turned. The dial indicator has a rotary dial for accurately measuring displacement. A moveable, biased probe translates longitudinally and drives the dial responsive to longitudinal motion of the probe. The dial indicator is typically affixed proximate a portion of the milling or turning machine and held in place by an adjustable frame. The probe is brought into contact with a moveable component of the milling or turning machine. Motion of the milling or turning machine with respect to the dial indicator causes longitudinal motion of the probe. Such motion is registered on the dial. The readout of the dial provides a measurement of the translation of the moveable component of the milling or turning machine. In this manner a dimension of a milling or turning operation can be accurately monitored.
A disadvantage of dial indicators is that they are fairly expensive devices, typically starting at about $400.00 apiece. It would be a decided advantage in the industry to have a device that would perform the function of the dial indicator, but cost substantially less.